Walboro 307 versus 340

[turbojimmy]

Originally posted by Mike Licht
If you pull the 307, take a punch and tighten up the overpressue valve spring you will have a 340. If you need help with this let me know. The replacment pump for the 340 is F20000169. This pump will out perform a 307 by a large margin and allow fuel pressure over 65 psi where the 307M rapidly drops off in performance.
Mike

Does the 340 replacement pump outperform the 340 as well?

My brother has a 340 that he hasn't installed for his otherwise bone stock car. I may buy it from him and give him my 307 unless the 340 replacement is substantially better than a 340.

Thanks for the info.

Jim

 

[Cheeseburger]

I have run consistant 11.1s with the 307 fuel pump and 009 inj's, I.M.H.O.---if you want to go faster i would not upgrade to a 340 but go to a dual intank setup.
Your 307 pump should take you to low 11s if you are running a heavy gauge upgraded wire to it and your voltage system is up to par.
Hope this helps.

 

[Ormand]

Mike Licht claims that you can "convert" a 307 into a 340 by increasing the relief spring pressure. But I understood, as 87GN mentioned, that the 340 had a motor change. The published pump curves show that the 340 draws less current at a give pressure/flow than the 307, which is good thing, and would support that the pumps have different motors. (Racetronix also states on their site that the 340/340M have a more efficient armature) Of course, if Walbor isn't offering a choice of pumps anymore, I guess it doesn't matter....

 

[JCotton]

how long did it take to run out on u when u were running 10.70s?



Can't say that I ran out, only that I ran consistently at 10.70 - 10.80 for a season plus. Again, based on actual use, I figured as long as I kept the voltage above 15 volts I received all the fuel I needed. The last pass I made with that combo was at Cecil County, Md. I lost my alternator in the middle of the run, as the voltage dropped so did my fuel flow as I recorded the run on my laptop. Voltage dropped, injector duty cycle increased, O2 reading leaned out...... My boost was around 26lbs, base fuel pressure was around 45lbs. My math adds up to 71lbs under boost. Worked for me............ those are my numbers for flow not based on the bench but at the track.

 

[87GN_70GS]

Does the 340 replacement pump outperform the 340 as well?

the 340 by using part # F20000169, same guts, same flow

Has the same guts, therefore, same flow. So the answer is no.

 

[turbojimmy]

Originally posted by 87GN_70GS
Has the same guts, therefore, same flow. So the answer is no.

Missed that - thanks.

Jim

 

[87GN_70GS]

~54.1 @ 12.2V vs. my ~42.3 @ 12.2V

When I tested my unshimmed 307 years ago, at 60 psi and 13.5v I got MORE than the walbro data; 58 gph to my 61 gph. I attribute the difference to me using a sample size of only one. I guess the message here is that to have "statistically significant" results, you need to test a number of pumps (if you have an endless suplly of $$) and average them; some will test more, some will test less. YMMV.

 

[JCotton]

I hate it when I screw up.............. My source for pumps explained the information about the Walbro pumps changes incorrectly to me last week. And here I sit thinking how smart I was.......... After reading through several posts I could see something was wrong so I just got off the phone again and have cleared things up in my head. as well as his. The 307 is the pump that is supposed to be discontinued, although rated at 255lph, guess walbro feels no need for it with the 340m. The 340m is now the F20000169, which will be the pump for the future. I should be getting all the specs for myself faxed over today from Walbro and will feel much better about the info once I have if in my hand and documented.
sorry if I passed any wrong figures out.

PS, I still like the 307................ it worked for me

 

[Cheeseburger]

I see the cows have not come home yet! LOL

 

[Dean]

87GN_70GS, I agree, a larger sampling would certainly be more definitive, but now knowing what I now know about THAT pump makes it kinda scary that there is such a wide margin. Like cars, I guess there are good ones and there are lemons, so I guess the safest thing to do if you swap pumps, ya might want to start a little more conservative. YMMV... how true!


JCotton, no doubt your 307 was good. The testing by PTE had these results (-6 feed line on a bench, NOT routed in a car, dunno what fuel rail, if any):

307 intank:
(major fuel was being bypassed thru the internal pressure spring)
- 14 volts "67"psi the pump delivered 5.77ppm enough for 692hp

Previous tested 307 pump with bypass repaired:
@14.16 volts 70psi the pump delivered 7.16ppm enough for 860hp

New 307 pump out of the box today:
@14.11 volts 70psi the pump delivered 5.78ppm enough for 693hp


Jack, since you are "connected", could you ask if there are any thoughts about an even better pump? Something with ~ 20% more volume (~65ghp) @ 70# & 13.5V would be lovely. Or is the body size the big limitation.

Dean

 

[JCotton]

Mooooooooo.............. the cows are still in the pasture, no doubt. We can reverse that first statement bout the 307 vs 340, the 307 is being discontinuied, so it won't matter much. Of course that is depending on whether I was fed the correct info. I'm waiting on the fax and we'll see what shows up.

 

[87GN_70GS]

could you ask if there are any thoughts about an even better pump?

The only ones I know of are not from Walbro, but A'PEXi and Denso. They are for import applications (Supra TT, Skyline) so would have to be modified to use. There was another thread on this earlier.

The Denso 195130-1020 would be called a "290 lph" pump, with 69 gph vs 66 gph for the Walbro 340 at 60 psi and 13.5v

The A'PEXi BNR32 or 404-A011 is a "315 lph" pump, with 80 gph at the same conditions. But it's about $360.

http://www.stealth316.com/2-fuelpumpguide.htm

 

[Racetronix]

The 307 and 340 are NOT discontinued.
The 'M'/machined versions of these pumps are.
The 340M has been replaced with the new F20000169 which has a new injection molded offset inlet similar to factory GM pumps.
The internal guts of the F20000169 are exactly the same as the 340 hence the same flow specs.

The reason for this change is that Walbro does not want to have to manually machine the ends of the pumps on a lathe. The price of the F20000169 is slightly higher than the 340M.

Racetronix WILL continue to offer the 'M' versions of these pumps.

Walbro has no plans to develop a higher output pump than the 34x series. The armature is the fastest one they make and the gear set is the largest that can fit in the current pump body.

A 307 which has had its check valve modified will not last as long as a 340 and will draw more current at the same given pressure & voltage.

Jack
Racetronix

 

[Dean]

Originally posted by Racetronix
The 340M has been replaced with the new F20000169 which has a new injection molded offset inlet similar to factory GM pumps.

<snipped>

The reason for this change is that Walbro does not want to have to manually machine the ends of the pumps on a lathe. The price of the F20000169 is slightly higher than the 340M.

Funny... save $ on manufacturing and then pass COSTS on to the comsumer?

Walbro has no plans to develop a higher output pump than the 34x series. The armature is the fastest one they make and the gear set is the largest that can fit in the current pump body.

That's what I though it might be. thanks, Jack.


Dean

 

[Racetronix]

Originally posted by Dean
Funny... save $ on manufacturing and then pass COSTS on to the comsumer?

That's what I though it might be. thanks, Jack.

Dean

Add to that a 3% price increase at the WD level and no factory warranty.